What is the difference between PVC and CPVC?
PVC piping is used for potable water systems and some chemicals depending upon the chemical resistance charts. Maximum operating temperature is 140ºF or 60ºC and pressure ratings drop with increase in temperature. CPVC pipe is used for potable water, acid and other chemicals with operating temperatures of up to 200ºF or 93ºC.
What is the difference between schedule 40 and schedule 80 pipe and fittings?
The biggest difference is in the wall thickness. Schedule 80 pipe is thicker walled but will fit into a schedule 40 fitting. Schedule 80 is most commonly used in industrial applications where a more robust piping system is required. Pools use schedule 40.
Also note:
• Schedule 40 pipe is available in both white and gray while schedule 80 is always gray.
• Schedule 80 can also be threaded. If you require threaded fittings, it is recommended to use schedule 80.
Do I need to use primer?
If you want to be certain that your joints have the least chance of failing, you must use primer. Primer is NOT a cleaner, it is a catalyst. When wet, it softens the PVC allowing for a true “solvent weld” by bonding not only with the cement but also with the PVC surfaces. It has been suggested that you only need to use primer if temperatures are under 5ºC. Well, it is true that you MUST use primer under those conditions however, it is highly recommended to use primer always and in many cases is required by code. Note also that primer must still be wet to be effective.
Why are some primers purple in color?
Purple primer is to be used for inspection purposes or if you want to have a visual cue that you did in fact use primer.
What is the difference between the types of cement?
Each piping system has a cement that is uniquely designed for that product. PVC Schedule 40 and 80 piping has a few types of cement available in clear and gray as well as a wet environment cement and a pool system cement. Your specific application requirements will determine the best cement for the job.
PVC Cement shall NOT be used on CPVC piping
For CPVC you MUST use CPVC cement, an orange tinted cement that is highly resistive to most chemicals. It can also be used on PVC and is recommended for all applications not involving water. You must use primer with this product.
There are additional cements for transition from other piping systems.
Is it ok to use PVC piping systems with pressurized air?
NEVER use compressed air or gas in PVC/CPVC/PP/PVDF pipe and fittings.
NEVER test PVC/CPVC/PP/PVDF pipe and fittings with compressed air or gas, or air-over-water boosters.
ONLY use PVC/CPVC/PP/PVDF pipe for water and approved chemicals.
WARNING! Vinyl Process Piping Systems
Use of compressed air or gas in PVC/CPVC/PP/PVDF pipe and fittings can result in explosive failures and cause severe injury or death.
Is there a difference between white schedule 40 PVC and Gray?
Typically there is little or no difference in the pipe if rated schedule 40 however there are a great number of manufacturers who make a number of different qualities of fittings.
White pipe and fittings do not stand up to UV very well whereas gray pipe has a higher resistance
Can I fix a leak by adding cement into the joint?
No. Some users have tried to use resins and fiberglass over the pipe and fittings but this is prone to failure as well. Best practice is to remove the leaking fittings and replace them. If that is not possible, you may have it welded by rope welding using three passes but this is best carried out by a specialist in plastic pipe welding. Our business partner, Plas-Tech Fabrications, offers this service in Eastern Ontario and Western Quebec. You can visit their website at www.pvcindustrialproducts.com or call (613) 831-4640.